Author
John R. Griffiths
Other affiliations: Lincoln's Inn, Hammersmith Hospital, Nottingham Trent University ...read more
Bio: John R. Griffiths is an academic researcher from University of Manchester. The author has contributed to research in topics: Carbogen & In vivo. The author has an hindex of 76, co-authored 356 publications receiving 23179 citations. Previous affiliations of John R. Griffiths include Lincoln's Inn & Hammersmith Hospital.
Papers published on a yearly basis
Papers
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TL;DR: Studying a mouse model of PDA that is refractory to the clinically used drug gemcitabine, it is found that the tumors in this model were poorly perfused and poorly vascularized, properties that are shared with human PDA.
Abstract: Pancreatic ductal adenocarcinoma (PDA) is among the most lethal human cancers in part because it is insensitive to many chemotherapeutic drugs. Studying a mouse model of PDA that is refractory to the clinically used drug gemcitabine, we found that the tumors in this model were poorly perfused and poorly vascularized, properties that are shared with human PDA. We tested whether the delivery and efficacy of gemcitabine in the mice could be improved by coadministration of IPI-926, a drug that depletes tumor-associated stromal tissue by inhibition of the Hedgehog cellular signaling pathway. The combination therapy produced a transient increase in intratumoral vascular density and intratumoral concentration of gemcitabine, leading to transient stabilization of disease. Thus, inefficient drug delivery may be an important contributor to chemoresistance in pancreatic cancer.
2,831 citations
TL;DR: The results suggest that the PI3K/Akt/TOR pathway regulates protein and lipid biosynthesis in an orchestrated manner and that both processes are required for cell growth.
1,143 citations
TL;DR: In this study, it is shown that FH-deficient cells and tumours accumulate fumarate and, to a lesser extent, succinate, and in situ analyses showed that these tumours also have over-expression of hypoxia-inducible factor 1alpha, activation of HIF1alphatargets, and high microvessel density.
Abstract: The nuclear-encoded Krebs cycle enzymes, fumarate hydratase (FH) and succinate dehydrogenase (SDHB, -C and -D), act as tumour suppressors. Germline mutations in FH predispose individuals to leiomyomas and renal cell cancer (HLRCC), whereas mutations in SDH cause paragangliomas and phaeochromocytomas (HPGL). In this study, we have shown that FH-deficient cells and tumours accumulate fumarate and, to a lesser extent, succinate. SDH-deficient tumours principally accumulate succinate. In situ analyses showed that these tumours also have over-expression of hypoxia-inducible factor 1alpha (HIF1alpha), activation of HIF1alphatargets (such as vascular endothelial growth factor) and high microvessel density. We found no evidence of increased reactive oxygen species in our cells. Our data provide in vivo evidence to support the hypothesis that increased succinate and/or fumarate causes stabilization of HIF1alpha a plausible mechanism, inhibition of HIF prolyl hydroxylases, has previously been suggested by in vitro studies. The basic mechanism of tumorigenesis in HPGL and HLRCC is likely to be pseudo-hypoxic drive, just as it is in von Hippel-Lindau syndrome.
832 citations
University of Manchester1, Imperial College London2, Central Manchester University Hospitals NHS Foundation Trust3, Ford Motor Company4, Harvard University5, King's College London6, University Medical Center Groningen7, University of Cambridge8, University of Oxford9, The Royal Marsden NHS Foundation Trust10, University of Leeds11, University of Michigan12, European Organisation for Research and Treatment of Cancer13, Institute of Cancer Research14, University College London15, United States Military Academy16, VU University Amsterdam17, University of Wisconsin-Madison18, Maastricht University19, Institut Gustave Roussy20, Robarts Research Institute21, Memorial Sloan Kettering Cancer Center22, Newcastle University23, University of Leicester24, Mount Vernon Hospital25, Johns Hopkins University26, Hofstra University27, University of Birmingham28, University of Antwerp29, Duke University30, Brighton and Sussex Medical School31, University of Sheffield32, University of Texas at Austin33
TL;DR: Experts assembled to review, debate and summarize the challenges of IB validation and qualification produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical validation, biological/clinical validation and assessment of cost-effectiveness.
Abstract: Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.
758 citations
TL;DR: Molecular genetic approaches have revealed hypoxia-induced coordinated upregulation of glycolysis, a potentially important mechanism for establishing the metabolic phenotype of tumours, and opening up new opportunities for therapy.
718 citations
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TL;DR: Recognition of the widespread applicability of these concepts will increasingly affect the development of new means to treat human cancer.
51,099 citations
01 Jan 2006
TL;DR: Probability distributions of linear models for regression and classification are given in this article, along with a discussion of combining models and combining models in the context of machine learning and classification.
Abstract: Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.
10,141 citations
01 Apr 2012
TL;DR: The mechanistic target of rapamycin (mTOR) signaling pathway senses and integrates a variety of environmental cues to regulate organismal growth and homeostasis as mentioned in this paper, and is implicated in an increasing number of pathological conditions, including cancer, obesity, type 2 diabetes, and neurodegeneration.
Abstract: The mechanistic target of rapamycin (mTOR) signaling pathway senses and integrates a variety of environmental cues to regulate organismal growth and homeostasis. The pathway regulates many major cellular processes and is implicated in an increasing number of pathological conditions, including cancer, obesity, type 2 diabetes, and neurodegeneration. Here, we review recent advances in our understanding of the mTOR pathway and its role in health, disease, and aging. We further discuss pharmacological approaches to treat human pathologies linked to mTOR deregulation.
6,268 citations
TL;DR: Recent advances in understanding of the mTOR pathway are reviewed and pharmacological approaches to treat human pathologies linked to mTOR deregulation are discussed.
5,792 citations
TL;DR: Recent advances in understanding of mTOR function, regulation, and importance in mammalian physiology are reviewed and how the mTOR signaling network contributes to human disease is highlighted.
4,719 citations